/*
 * Copyright 2019 Google LLC
 *
 * Use of this source code is governed by a BSD-style license that can be
 * found in the LICENSE file.
 */

#include "include/core/SkColor.h"
#include "include/core/SkFontStyle.h"
#include "include/core/SkPictureRecorder.h"
#include "include/core/SkString.h"

#include "modules/skparagraph/include/DartTypes.h"
#include "modules/skparagraph/include/Paragraph.h"
#include "modules/skparagraph/include/TextStyle.h"
#include "modules/skparagraph/include/TypefaceFontProvider.h"
#include "modules/skparagraph/src/ParagraphBuilderImpl.h"
#include "modules/skparagraph/src/ParagraphImpl.h"

#include <string>
#include <vector>

#include <emscripten.h>
#include <emscripten/bind.h>
#include "modules/canvaskit/WasmCommon.h"

using namespace emscripten;
using namespace skia_private;

namespace para = skia::textlayout;

// switch to ptrToSkColor4f (canvaskit_bindings.cpp)
SkColor4f toSkColor4f(WASMPointerF32 cPtr)
{
    float *fourFloats = reinterpret_cast<float *>(cPtr);
    SkColor4f color = { fourFloats[0], fourFloats[1], fourFloats[2], fourFloats[3] };
    return color;
}

struct SimpleFontStyle {
    SkFontStyle::Slant slant;
    SkFontStyle::Weight weight;
    SkFontStyle::Width width;
};

struct SimpleTextStyle {
    WASMPointerF32 colorPtr;
    WASMPointerF32 foregroundColorPtr;
    WASMPointerF32 backgroundColorPtr;
    uint8_t decoration;
    SkScalar decorationThickness;
    WASMPointerF32 decorationColorPtr;
    para::TextDecorationStyle decorationStyle;
    para::TextBaseline textBaseline;
    SkScalar fontSize;
    SkScalar letterSpacing;
    SkScalar wordSpacing;
    SkScalar heightMultiplier;
    bool halfLeading;
    WASMPointerU8 localePtr;
    int localeLen;
    SimpleFontStyle fontStyle;

    WASMPointerU8 fontFamiliesPtr;
    int fontFamiliesLen;

    int shadowLen;
    WASMPointerF32 shadowColorsPtr;
    WASMPointerF32 shadowOffsetsPtr;
    WASMPointerF32 shadowBlurRadiiPtr;

    int fontFeatureLen;
    WASMPointerF32 fontFeatureNamesPtr;
    WASMPointerF32 fontFeatureValuesPtr;

    int fontVariationLen;
    WASMPointerF32 fontVariationAxesPtr;
    WASMPointerF32 fontVariationValuesPtr;
};

struct SimpleStrutStyle {
    WASMPointerU32 fontFamiliesPtr;
    int fontFamiliesLen;
    SimpleFontStyle fontStyle;
    SkScalar fontSize;
    SkScalar heightMultiplier;
    bool halfLeading;
    SkScalar leading;
    bool strutEnabled;
    bool forceStrutHeight;
};

para::StrutStyle toStrutStyle(const SimpleStrutStyle &s)
{
    para::StrutStyle ss;

    const char **fontFamilies = reinterpret_cast<const char **>(s.fontFamiliesPtr);
    if (fontFamilies != nullptr) {
        std::vector<SkString> ff;
        for (int i = 0; i < s.fontFamiliesLen; i++) {
            ff.emplace_back(fontFamilies[i]);
        }
        ss.setFontFamilies(ff);
    }

    SkFontStyle fs(s.fontStyle.weight, s.fontStyle.width, s.fontStyle.slant);
    ss.setFontStyle(fs);

    if (s.fontSize != -1) {
        ss.setFontSize(s.fontSize);
    }
    if (s.heightMultiplier != -1) {
        ss.setHeight(s.heightMultiplier);
        ss.setHeightOverride(true);
    }
    ss.setHalfLeading(s.halfLeading);

    if (s.leading != 0) {
        ss.setLeading(s.leading);
    }

    ss.setStrutEnabled(s.strutEnabled);
    ss.setForceStrutHeight(s.forceStrutHeight);

    return ss;
}

para::TextStyle toTextStyle(const SimpleTextStyle &s)
{
    para::TextStyle ts;

    // textstyle.color doesn't support a 4f color, however the foreground and background fields
    // below do.
    ts.setColor(toSkColor4f(s.colorPtr).toSkColor());

    // It is functionally important that these paints be unset when no value was provided.
    if (s.foregroundColorPtr) {
        SkPaint p1;
        p1.setColor4f(toSkColor4f(s.foregroundColorPtr));
        ts.setForegroundColor(p1);
    }

    if (s.backgroundColorPtr) {
        SkPaint p2;
        p2.setColor4f(toSkColor4f(s.backgroundColorPtr));
        ts.setBackgroundColor(p2);
    }

    if (s.fontSize != -1) {
        ts.setFontSize(s.fontSize);
    }
    if (s.letterSpacing != 0) {
        ts.setLetterSpacing(s.letterSpacing);
    }
    if (s.wordSpacing != 0) {
        ts.setWordSpacing(s.wordSpacing);
    }

    if (s.heightMultiplier != -1) {
        ts.setHeight(s.heightMultiplier);
        ts.setHeightOverride(true);
    }

    ts.setHalfLeading(s.halfLeading);

    ts.setDecoration(para::TextDecoration(s.decoration));
    ts.setDecorationStyle(s.decorationStyle);
    if (s.decorationThickness != 0) {
        ts.setDecorationThicknessMultiplier(s.decorationThickness);
    }
    if (s.decorationColorPtr) {
        ts.setDecorationColor(toSkColor4f(s.decorationColorPtr).toSkColor());
    }

    if (s.localeLen > 0) {
        const char *localePtr = reinterpret_cast<const char *>(s.localePtr);
        SkString lStr(localePtr, s.localeLen);
        ts.setLocale(lStr);
    }

    const char **fontFamilies = reinterpret_cast<const char **>(s.fontFamiliesPtr);
    if (fontFamilies != nullptr) {
        std::vector<SkString> ff;
        for (int i = 0; i < s.fontFamiliesLen; i++) {
            ff.emplace_back(fontFamilies[i]);
        }
        ts.setFontFamilies(ff);
    }

    ts.setTextBaseline(s.textBaseline);

    SkFontStyle fs(s.fontStyle.weight, s.fontStyle.width, s.fontStyle.slant);
    ts.setFontStyle(fs);

    if (s.shadowLen > 0) {
        const SkColor4f *colors = reinterpret_cast<const SkColor4f *>(s.shadowColorsPtr);
        const SkPoint *offsets = reinterpret_cast<const SkPoint *>(s.shadowOffsetsPtr);
        const float *blurRadii = reinterpret_cast<const float *>(s.shadowBlurRadiiPtr);
        for (int i = 0; i < s.shadowLen; i++) {
            para::TextShadow shadow(colors[i].toSkColor(), offsets[i], blurRadii[i]);
            ts.addShadow(shadow);
        }
    }


    if (s.fontFeatureLen > 0) {
        const char **fontFeatureNames = reinterpret_cast<const char **>(s.fontFeatureNamesPtr);
        const int *fontFeatureValues = reinterpret_cast<const int *>(s.fontFeatureValuesPtr);
        for (int i = 0; i < s.fontFeatureLen; i++) {
            // Font features names are 4-character simple strings.
            SkString name(fontFeatureNames[i], 4);
            ts.addFontFeature(name, fontFeatureValues[i]);
        }
    }

    if (s.fontVariationLen > 0) {
        const char **fontVariationAxes = reinterpret_cast<const char **>(s.fontVariationAxesPtr);
        const float *fontVariationValues = reinterpret_cast<const float *>(s.fontVariationValuesPtr);
        std::vector<SkFontArguments::VariationPosition::Coordinate> coordinates;
        for (int i = 0; i < s.fontVariationLen; i++) {
            // Font variation axis tags are 4-character simple strings.
            SkString axis(fontVariationAxes[i]);
            if (axis.size() != 4) {
                continue;
            }
            coordinates.push_back({ SkSetFourByteTag(axis[0], axis[1], axis[2], axis[3]), fontVariationValues[i] });
        }
        SkFontArguments::VariationPosition position = { coordinates.data(), static_cast<int>(coordinates.size()) };
        ts.setFontArguments(SkFontArguments().setVariationDesignPosition(position));
    }

    return ts;
}

struct SimpleParagraphStyle {
    bool disableHinting;
    WASMPointerU8 ellipsisPtr;
    size_t ellipsisLen;
    SkScalar heightMultiplier;
    size_t maxLines;
    bool replaceTabCharacters;
    para::TextAlign textAlign;
    para::TextDirection textDirection;
    para::TextHeightBehavior textHeightBehavior;
    SimpleTextStyle textStyle;
    SimpleStrutStyle strutStyle;
    bool applyRoundingHack;
};

para::ParagraphStyle toParagraphStyle(const SimpleParagraphStyle &s)
{
    para::ParagraphStyle ps;
    if (s.disableHinting) {
        ps.turnHintingOff();
    }

    if (s.ellipsisLen > 0) {
        const char *ellipsisPtr = reinterpret_cast<const char *>(s.ellipsisPtr);
        SkString eStr(ellipsisPtr, s.ellipsisLen);
        ps.setEllipsis(eStr);
    }
    ps.setTextAlign(s.textAlign);
    ps.setTextDirection(s.textDirection);
    auto ts = toTextStyle(s.textStyle);
    ps.setTextStyle(ts);
    auto ss = toStrutStyle(s.strutStyle);
    ps.setStrutStyle(ss);
    if (s.heightMultiplier != -1) {
        ps.setHeight(s.heightMultiplier);
    }
    if (s.maxLines != 0) {
        ps.setMaxLines(s.maxLines);
    }
    ps.setApplyRoundingHack(s.applyRoundingHack);
    ps.setTextHeightBehavior(s.textHeightBehavior);
    ps.setReplaceTabCharacters(s.replaceTabCharacters);
    return ps;
}

struct SimpleTextBox {
    SkRect rect;
    // This isn't the most efficient way to represent this, but it is much easier to keep
    // everything as floats when unpacking on the JS side.
    // 0.0 = RTL, 1.0 = LTr
    SkScalar direction;
};

Float32Array TextBoxesToFloat32Array(std::vector<para::TextBox> boxes)
{
    // Pack these text boxes into an array of n groups of 5 SkScalar (floats)
    if (!boxes.size()) {
        return emscripten::val::null();
    }
    SimpleTextBox *rects = new SimpleTextBox[boxes.size()];
    for (size_t i = 0; i < boxes.size(); i++) {
        rects[i].rect = boxes[i].rect;
        if (boxes[i].direction == para::TextDirection::kRtl) {
            rects[i].direction = 0;
        } else {
            rects[i].direction = 1;
        }
    }
    float *fPtr = reinterpret_cast<float *>(rects);
    // Of note: now that we have cast rects to float*, emscripten is smart enough to wrap this
    // into a Float32Array for us.
    return Float32Array(typed_memory_view(boxes.size() * 5, fPtr));
}

Float32Array GetRectsForRange(para::Paragraph &self, unsigned start, unsigned end, para::RectHeightStyle heightStyle,
    para::RectWidthStyle widthStyle)
{
    std::vector<para::TextBox> boxes = self.getRectsForRange(start, end, heightStyle, widthStyle);
    return TextBoxesToFloat32Array(boxes);
}

Float32Array GetRectsForPlaceholders(para::Paragraph &self)
{
    std::vector<para::TextBox> boxes = self.getRectsForPlaceholders();
    return TextBoxesToFloat32Array(boxes);
}

JSObject JSObjectFromLineMetrics(skia::textlayout::LineMetrics &metrics)
{
    JSObject m = emscripten::val::object();
    m.set("startIndex", metrics.fStartIndex);
    m.set("endIndex", metrics.fEndIndex);
    m.set("endExcludingWhitespaces", metrics.fEndExcludingWhitespaces);
    m.set("endIncludingNewline", metrics.fEndIncludingNewline);
    m.set("isHardBreak", metrics.fHardBreak);
    m.set("ascent", metrics.fAscent);
    m.set("descent", metrics.fDescent);
    m.set("height", metrics.fHeight);
    m.set("width", metrics.fWidth);
    m.set("left", metrics.fLeft);
    m.set("baseline", metrics.fBaseline);
    m.set("lineNumber", metrics.fLineNumber);
    return m;
}

JSObject JSObjectFromGlyphInfo(skia::textlayout::Paragraph::GlyphInfo &glyphInfo)
{
    JSObject object = emscripten::val::object();

    JSObject range = emscripten::val::object();
    range.set("start", glyphInfo.fGraphemeClusterTextRange.start);
    range.set("end", glyphInfo.fGraphemeClusterTextRange.end);
    object.set("graphemeClusterTextRange", range);

    JSArray rect = emscripten::val::array();
    rect.call<void>("push", glyphInfo.fGraphemeLayoutBounds.left());
    rect.call<void>("push", glyphInfo.fGraphemeLayoutBounds.top());
    rect.call<void>("push", glyphInfo.fGraphemeLayoutBounds.right());
    rect.call<void>("push", glyphInfo.fGraphemeLayoutBounds.bottom());
    object.set("graphemeLayoutBounds", rect);

    object.set("dir", glyphInfo.fDirection == skia::textlayout::TextDirection::kRtl ? 0 : 1);
    object.set("isEllipsis", glyphInfo.fIsEllipsis);
    return object;
}

JSArray GetLineMetrics(para::Paragraph &self)
{
    std::vector<skia::textlayout::LineMetrics> metrics;
    self.getLineMetrics(metrics);
    JSArray result = emscripten::val::array();
    for (auto metric : metrics) {
        result.call<void>("push", JSObjectFromLineMetrics(metric));
    }
    return result;
}

JSObject GetLineMetricsAt(para::Paragraph &self, size_t lineNumber)
{
    skia::textlayout::LineMetrics metrics;
    return self.getLineMetricsAt(lineNumber, &metrics) ? JSObjectFromLineMetrics(metrics) : emscripten::val::null();
}

JSObject GetGlyphInfoAt(para::Paragraph &self, size_t index)
{
    skia::textlayout::Paragraph::GlyphInfo glyphInfo;
    return self.getGlyphInfoAtUTF16Offset(index, &glyphInfo) ? JSObjectFromGlyphInfo(glyphInfo) :
                                                               emscripten::val::null();
}

JSObject GetClosestGlyphInfoAtCoordinate(para::Paragraph &self, SkScalar dx, SkScalar dy)
{
    skia::textlayout::Paragraph::GlyphInfo glyphInfo;
    return self.getClosestUTF16GlyphInfoAt(dx, dy, &glyphInfo) ? JSObjectFromGlyphInfo(glyphInfo) :
                                                                 emscripten::val::null();
}

/*
 * Returns Lines[]
 */
JSArray GetShapedLines(para::Paragraph &self)
{
    struct LineAccumulate {
        int lineNumber = -1; // deliberately -1 from starting value
        uint32_t minOffset = 0xFFFFFFFF;
        uint32_t maxOffset = 0;
        float minAscent = 0;
        float maxDescent = 0;
        // not really accumulated, but definitely set
        float baseline = 0;

        void reset(int newLineNum)
        {
            new (this) LineAccumulate;
            this->lineNumber = newLineNum;
        }
    };

    // where we accumulate our js output
    JSArray jlines = emscripten::val::array();
    JSObject jline = emscripten::val::null();
    JSArray jruns = emscripten::val::null();
    LineAccumulate accum;

    self.visit([&](int lineNumber, const para::Paragraph::VisitorInfo *info) {
        if (!info) {
            if (!jline)
                return; // how???
            // end of current line
            JSObject range = emscripten::val::object();
            range.set("first", accum.minOffset);
            range.set("last", accum.maxOffset);
            jline.set("textRange", range);

            jline.set("top", accum.baseline + accum.minAscent);
            jline.set("bottom", accum.baseline + accum.maxDescent);
            jline.set("baseline", accum.baseline);
            return;
        }

        if (lineNumber != accum.lineNumber) {
            SkASSERT(lineNumber == accum.lineNumber + 1); // assume monotonic

            accum.reset(lineNumber);
            jruns = emscripten::val::array();

            jline = emscripten::val::object();
            jline.set("runs", jruns);
            // will assign textRange and metrics on end-of-line signal

            jlines.call<void>("push", jline);
        }

        // append the run
        const int N = info->count; // glyphs
        const int N1 = N + 1;      // positions, offsets have 1 extra (trailing) slot

        JSObject jrun = emscripten::val::object();

        jrun.set("flags", info->flags);

        // TODO: figure out how to set a wrapped sk_sp<SkTypeface>
        //        jrun.set("typeface", info->font.getTypeface());
        jrun.set("typeface", emscripten::val::null());
        jrun.set("size", info->font.getSize());
        if (info->font.getScaleX()) {
            jrun.set("scaleX", info->font.getScaleX());
        }

        jrun.set("glyphs", MakeTypedArray(N, info->glyphs));
        jrun.set("offsets", MakeTypedArray(N1, info->utf8Starts));

        // we need to modify the positions, so make a temp copy
        AutoSTMalloc<32, SkPoint> positions(N1);
        for (int i = 0; i < N; ++i) {
            positions.get()[i] = info->positions[i] + info->origin;
        }
        positions.get()[N] = { info->advanceX, positions.get()[N - 1].fY };
        jrun.set("positions", MakeTypedArray(N1 * 2, (const float *)positions.get()));

        jruns.call<void>("push", jrun);

        // update accum
        {
            SkFontMetrics fm;
            info->font.getMetrics(&fm);

            accum.minAscent = std::min(accum.minAscent, fm.fAscent);
            accum.maxDescent = std::max(accum.maxDescent, fm.fDescent);
            accum.baseline = info->origin.fY;

            accum.minOffset = std::min(accum.minOffset, info->utf8Starts[0]);
            accum.maxOffset = std::max(accum.maxOffset, info->utf8Starts[N]);
        }
    });
    return jlines;
}

std::vector<SkUnicode::Position> convertArrayU32(WASMPointerU32 array, size_t count)
{
    std::vector<size_t> vec;
    vec.resize(count);
    SkUnicode::Position *data = reinterpret_cast<SkUnicode::Position *>(array);
    std::memcpy(vec.data(), data, count * sizeof(size_t));
    return vec;
}

JSArray UnresolvedCodepoints(para::Paragraph &self)
{
    JSArray result = emscripten::val::array();
    for (auto cp : self.unresolvedCodepoints()) {
        result.call<void>("push", cp);
    }
    return result;
}

EMSCRIPTEN_BINDINGS(Paragraph)
{
    class_<para::Paragraph>("Paragraph")
        .function("didExceedMaxLines", &para::Paragraph::didExceedMaxLines)
        .function("getAlphabeticBaseline", &para::Paragraph::getAlphabeticBaseline)
        .function("getGlyphPositionAtCoordinate", &para::Paragraph::getGlyphPositionAtCoordinate)
        .function("getHeight", &para::Paragraph::getHeight)
        .function("getIdeographicBaseline", &para::Paragraph::getIdeographicBaseline)
        .function("getLineMetrics", &GetLineMetrics)
        .function("getLineMetricsAt", &GetLineMetricsAt)
        .function("getLineNumberAt", &para::Paragraph::getLineNumberAt)
        .function("getLongestLine", &para::Paragraph::getLongestLine)
        .function("getMaxIntrinsicWidth", &para::Paragraph::getMaxIntrinsicWidth)
        .function("getMaxWidth", &para::Paragraph::getMaxWidth)
        .function("getMinIntrinsicWidth", &para::Paragraph::getMinIntrinsicWidth)
        .function("getNumberOfLines", &para::Paragraph::lineNumber)
        .function("_getClosestGlyphInfoAtCoordinate", &GetClosestGlyphInfoAtCoordinate)
        .function("_getGlyphInfoAt", &GetGlyphInfoAt)
        .function("_getRectsForPlaceholders", &GetRectsForPlaceholders)
        .function("_getRectsForRange", &GetRectsForRange)
        .function("getShapedLines", &GetShapedLines)
        .function("getWordBoundary", &para::Paragraph::getWordBoundary)
        .function("layout", &para::Paragraph::layout)
        .function("unresolvedCodepoints", &UnresolvedCodepoints);

    class_<para::ParagraphBuilderImpl>("ParagraphBuilder")
        .class_function("_Make",
        optional_override(
        [](SimpleParagraphStyle style, sk_sp<SkFontMgr> fontMgr) -> std::unique_ptr<para::ParagraphBuilderImpl> {
            auto fc = sk_make_sp<para::FontCollection>();
            fc->setDefaultFontManager(fontMgr);
            fc->enableFontFallback();
            auto ps = toParagraphStyle(style);
            auto pb = para::ParagraphBuilderImpl::make(ps, fc);
            return std::unique_ptr<para::ParagraphBuilderImpl>(static_cast<para::ParagraphBuilderImpl *>(pb.release()));
        }),
        allow_raw_pointers())
        .class_function("_MakeFromFontProvider",
        optional_override([](SimpleParagraphStyle style,
        sk_sp<para::TypefaceFontProvider> fontProvider) -> std::unique_ptr<para::ParagraphBuilderImpl> {
                            auto fc = sk_make_sp<para::FontCollection>();
                            fc->setDefaultFontManager(fontProvider);
                            fc->enableFontFallback();
                            auto ps = toParagraphStyle(style);
                            auto pb = para::ParagraphBuilderImpl::make(ps, fc);
                            return std::unique_ptr<para::ParagraphBuilderImpl>(
                                static_cast<para::ParagraphBuilderImpl *>(pb.release()));
                        }),
        allow_raw_pointers())
        .class_function("_MakeFromFontCollection",
        optional_override([](SimpleParagraphStyle style,
        sk_sp<para::FontCollection> fontCollection) -> std::unique_ptr<para::ParagraphBuilderImpl> {
                            auto ps = toParagraphStyle(style);
                            auto pb = para::ParagraphBuilderImpl::make(ps, fontCollection);
                            return std::unique_ptr<para::ParagraphBuilderImpl>(
                                static_cast<para::ParagraphBuilderImpl *>(pb.release()));
                        }),
        allow_raw_pointers())
        .class_function("_ShapeText", optional_override([](JSString jtext, JSArray jruns, float width) -> JSArray {
                            std::string textStorage = jtext.as<std::string>();
                            const char *text = textStorage.data();
                            size_t textCount = textStorage.size();

                            auto fc = sk_make_sp<para::FontCollection>();
                            fc->setDefaultFontManager(SkFontMgr::RefEmpty());
                            fc->enableFontFallback();

                            para::ParagraphStyle pstyle;
                            {
                                // For the most part this is ignored, since we set an explicit TextStyle
                                // for all of our text runs, but it is required by SkParagraph.
                                para::TextStyle style;
                                style.setFontFamilies({ SkString("sans-serif") });
                                style.setFontSize(32);
                                pstyle.setTextStyle(style);
                            }

                            auto pb = para::ParagraphBuilder::make(pstyle, fc);

                            // tease apart the FontBlock runs
                            size_t runCount = jruns["length"].as<size_t>();
                            for (size_t i = 0; i < runCount; ++i) {
                                emscripten::val r = jruns[i];

                                para::TextStyle style;
                                style.setTypeface(r["typeface"].as<sk_sp<SkTypeface>>());
                                style.setFontSize(r["size"].as<float>());

                                const size_t subTextCount = r["length"].as<size_t>();
                                if (subTextCount > textCount) {
                                    return emscripten::val("block runs exceed text length!");
                                }

                                pb->pushStyle(style);
                                pb->addText(text, subTextCount);
                                pb->pop();

                                text += subTextCount;
                                textCount -= subTextCount;
                            }
                            if (textCount != 0) {
                                return emscripten::val("Didn't have enough block runs to cover text");
                            }

                            auto pa = pb->Build();
                            pa->layout(width);

                            // workaround until this is fixed in SkParagraph
                            {
                                SkPictureRecorder rec;
                                pa->paint(rec.beginRecording({ 0, 0, 9999, 9999 }), 0, 0);
                            }
                            return GetShapedLines(*pa);
                        }),
        allow_raw_pointers())
        .class_function("RequiresClientICU", &para::ParagraphBuilderImpl::RequiresClientICU)
        .function("addText", optional_override(
        [](para::ParagraphBuilderImpl &self, std::string text) { return self.addText(text.c_str(), text.length()); }))
        .function("build", &para::ParagraphBuilderImpl::Build, allow_raw_pointers())
        .function("pop", &para::ParagraphBuilderImpl::pop)
        .function("reset", &para::ParagraphBuilderImpl::Reset, allow_raw_pointers())
        .function("_pushStyle", optional_override([](para::ParagraphBuilderImpl &self, SimpleTextStyle textStyle) {
                      auto ts = toTextStyle(textStyle);
                      self.pushStyle(ts);
                  }))
        // A method of pushing a textStyle with paints instead of colors for foreground and
        // background. Since SimpleTextStyle is a value object, it cannot contain paints, which
        // are not primitives. This binding is here to accept them. Any color that is specified
        // in the textStyle is overridden.
        .function("_pushPaintStyle", optional_override(
        [](para::ParagraphBuilderImpl &self, SimpleTextStyle textStyle, SkPaint foreground, SkPaint background) {
            auto ts = toTextStyle(textStyle);
            ts.setForegroundColor(foreground);
            ts.setBackgroundColor(background);
            self.pushStyle(ts);
        }))
        .function("_addPlaceholder", optional_override([](para::ParagraphBuilderImpl &self, SkScalar width,
        SkScalar height, para::PlaceholderAlignment alignment, para::TextBaseline baseline, SkScalar offset) {
                      para::PlaceholderStyle ps(width, height, alignment, baseline, offset);
                      self.addPlaceholder(ps);
                  }))
        .function("getText", optional_override([](para::ParagraphBuilderImpl &self) -> JSString {
                      auto text = self.getText();
                      return emscripten::val(std::string(text.data(), text.size()).c_str());
                  }))
        .function("_setWordsUtf8", optional_override([](para::ParagraphBuilderImpl &self, WASMPointerU32 clientWords,
        size_t wordsNum) { self.setWordsUtf8(convertArrayU32(clientWords, wordsNum)); }))
        .function("_setWordsUtf16", optional_override([](para::ParagraphBuilderImpl &self, WASMPointerU32 clientWords,
        size_t wordsNum) { self.setWordsUtf16(convertArrayU32(clientWords, wordsNum)); }))
        .function("_setGraphemeBreaksUtf8",
        optional_override([](para::ParagraphBuilderImpl &self, WASMPointerU32 clientGraphemes, size_t graphemesNum) {
                      self.setGraphemeBreaksUtf8(convertArrayU32(clientGraphemes, graphemesNum));
                  }))
        .function("_setGraphemeBreaksUtf16",
        optional_override([](para::ParagraphBuilderImpl &self, WASMPointerU32 clientGraphemes, size_t graphemesNum) {
                      self.setGraphemeBreaksUtf16(convertArrayU32(clientGraphemes, graphemesNum));
                  }))
        .function("_setLineBreaksUtf8",
        optional_override([](para::ParagraphBuilderImpl &self, WASMPointerU32 clientLineBreaks, size_t lineBreaksNum) {
                      SkUnicode::Position *lineBreakData = reinterpret_cast<SkUnicode::Position *>(clientLineBreaks);
                      std::vector<SkUnicode::LineBreakBefore> lineBreaks;
                      for (size_t i = 0; i < lineBreaksNum; i += 2) {
                          auto pos = lineBreakData[i];
                          auto breakType = lineBreakData[i + 1];
                          if (breakType == 0) {
                              lineBreaks.emplace_back(pos, SkUnicode::LineBreakType::kSoftLineBreak);
                          } else {
                              lineBreaks.emplace_back(pos, SkUnicode::LineBreakType::kHardLineBreak);
                          }
                      }
                      self.setLineBreaksUtf8(std::move(lineBreaks));
                  }))
        .function("_setLineBreaksUtf16",
        optional_override([](para::ParagraphBuilderImpl &self, WASMPointerU32 clientLineBreaks, size_t lineBreaksNum) {
                      SkUnicode::Position *lineBreakData = reinterpret_cast<SkUnicode::Position *>(clientLineBreaks);
                      std::vector<SkUnicode::LineBreakBefore> lineBreaks;
                      for (size_t i = 0; i < lineBreaksNum; i += 2) {
                          auto pos = lineBreakData[i];
                          auto breakType = lineBreakData[i + 1];
                          if (breakType == 0) {
                              lineBreaks.emplace_back(pos, SkUnicode::LineBreakType::kSoftLineBreak);
                          } else {
                              lineBreaks.emplace_back(pos, SkUnicode::LineBreakType::kHardLineBreak);
                          }
                      }
                      self.setLineBreaksUtf16(std::move(lineBreaks));
                  }));

    class_<para::TypefaceFontProvider, base<SkFontMgr>>("TypefaceFontProvider")
        .smart_ptr<sk_sp<para::TypefaceFontProvider>>("sk_sp<TypefaceFontProvider>")
        .class_function("Make", optional_override(
        []() -> sk_sp<para::TypefaceFontProvider> { return sk_make_sp<para::TypefaceFontProvider>(); }))
        .function("_registerFont",
        optional_override([](para::TypefaceFontProvider &self, sk_sp<SkTypeface> typeface, WASMPointerU8 familyPtr) {
                      const char *fPtr = reinterpret_cast<const char *>(familyPtr);
                      SkString fStr(fPtr);
                      self.registerTypeface(typeface, fStr);
                  }),
        allow_raw_pointers());

    class_<para::FontCollection>("FontCollection")
        .smart_ptr<sk_sp<para::FontCollection>>("sk_sp<FontCollection>")
        .class_function("Make",
        optional_override([]() -> sk_sp<para::FontCollection> { return sk_make_sp<para::FontCollection>(); }))
        .function("setDefaultFontManager",
        optional_override([](para::FontCollection &self, const sk_sp<para::TypefaceFontProvider> &fontManager) {
                      self.setDefaultFontManager(fontManager);
                  }),
        allow_raw_pointers())
        .function("enableFontFallback", &para::FontCollection::enableFontFallback);

    // These value objects make it easier to send data across the wire.
    value_object<para::PositionWithAffinity>("PositionWithAffinity")
        .field("pos", &para::PositionWithAffinity::position)
        .field("affinity", &para::PositionWithAffinity::affinity);

    value_object<SimpleFontStyle>("FontStyle")
        .field("slant", &SimpleFontStyle::slant)
        .field("weight", &SimpleFontStyle::weight)
        .field("width", &SimpleFontStyle::width);

    value_object<SimpleParagraphStyle>("ParagraphStyle")
        .field("disableHinting", &SimpleParagraphStyle::disableHinting)
        .field("_ellipsisPtr", &SimpleParagraphStyle::ellipsisPtr)
        .field("_ellipsisLen", &SimpleParagraphStyle::ellipsisLen)
        .field("heightMultiplier", &SimpleParagraphStyle::heightMultiplier)
        .field("maxLines", &SimpleParagraphStyle::maxLines)
        .field("replaceTabCharacters", &SimpleParagraphStyle::replaceTabCharacters)
        .field("textAlign", &SimpleParagraphStyle::textAlign)
        .field("textDirection", &SimpleParagraphStyle::textDirection)
        .field("textHeightBehavior", &SimpleParagraphStyle::textHeightBehavior)
        .field("textStyle", &SimpleParagraphStyle::textStyle)
        .field("strutStyle", &SimpleParagraphStyle::strutStyle)
        .field("applyRoundingHack", &SimpleParagraphStyle::applyRoundingHack);

    value_object<SimpleStrutStyle>("StrutStyle")
        .field("_fontFamiliesPtr", &SimpleStrutStyle::fontFamiliesPtr)
        .field("_fontFamiliesLen", &SimpleStrutStyle::fontFamiliesLen)
        .field("strutEnabled", &SimpleStrutStyle::strutEnabled)
        .field("fontSize", &SimpleStrutStyle::fontSize)
        .field("fontStyle", &SimpleStrutStyle::fontStyle)
        .field("heightMultiplier", &SimpleStrutStyle::heightMultiplier)
        .field("halfLeading", &SimpleStrutStyle::halfLeading)
        .field("leading", &SimpleStrutStyle::leading)
        .field("forceStrutHeight", &SimpleStrutStyle::forceStrutHeight);

    value_object<SimpleTextStyle>("TextStyle")
        .field("_colorPtr", &SimpleTextStyle::colorPtr)
        .field("_foregroundColorPtr", &SimpleTextStyle::foregroundColorPtr)
        .field("_backgroundColorPtr", &SimpleTextStyle::backgroundColorPtr)
        .field("decoration", &SimpleTextStyle::decoration)
        .field("decorationThickness", &SimpleTextStyle::decorationThickness)
        .field("_decorationColorPtr", &SimpleTextStyle::decorationColorPtr)
        .field("decorationStyle", &SimpleTextStyle::decorationStyle)
        .field("_fontFamiliesPtr", &SimpleTextStyle::fontFamiliesPtr)
        .field("_fontFamiliesLen", &SimpleTextStyle::fontFamiliesLen)
        .field("fontSize", &SimpleTextStyle::fontSize)
        .field("letterSpacing", &SimpleTextStyle::letterSpacing)
        .field("wordSpacing", &SimpleTextStyle::wordSpacing)
        .field("heightMultiplier", &SimpleTextStyle::heightMultiplier)
        .field("halfLeading", &SimpleTextStyle::halfLeading)
        .field("_localePtr", &SimpleTextStyle::localePtr)
        .field("_localeLen", &SimpleTextStyle::localeLen)
        .field("fontStyle", &SimpleTextStyle::fontStyle)
        .field("_shadowLen", &SimpleTextStyle::shadowLen)
        .field("_shadowColorsPtr", &SimpleTextStyle::shadowColorsPtr)
        .field("_shadowOffsetsPtr", &SimpleTextStyle::shadowOffsetsPtr)
        .field("_shadowBlurRadiiPtr", &SimpleTextStyle::shadowBlurRadiiPtr)
        .field("_fontFeatureLen", &SimpleTextStyle::fontFeatureLen)
        .field("_fontFeatureNamesPtr", &SimpleTextStyle::fontFeatureNamesPtr)
        .field("_fontFeatureValuesPtr", &SimpleTextStyle::fontFeatureValuesPtr)
        .field("_fontVariationLen", &SimpleTextStyle::fontVariationLen)
        .field("_fontVariationAxesPtr", &SimpleTextStyle::fontVariationAxesPtr)
        .field("_fontVariationValuesPtr", &SimpleTextStyle::fontVariationValuesPtr);

    // The U stands for unsigned - we can't bind a generic/template object, so we have to specify it
    // with the type we are using.
    // TODO(kjlubick) make this a typedarray.
    value_object<para::SkRange<size_t>>("URange")
        .field("start", &para::SkRange<size_t>::start)
        .field("end", &para::SkRange<size_t>::end);

    // TextDecoration should be a const because they can be combined
    constant("NoDecoration", int(para::TextDecoration::kNoDecoration));
    constant("UnderlineDecoration", int(para::TextDecoration::kUnderline));
    constant("OverlineDecoration", int(para::TextDecoration::kOverline));
    constant("LineThroughDecoration", int(para::TextDecoration::kLineThrough));
}
